1. Field of the Invention
The present invention relates to a wireless communication module capable of radiating a high frequency signal from an antenna coil, and a communication terminal apparatus including such a wireless communication module.
2. Description of the Related Art
Conventionally, an authentication technology by use of wireless communication such as RFID (Radio Frequency Identification)) is widely used in logistics management, credit transactions, and the like. In a RFID system, wireless communication is performed between a reader-writer and a RFID tag or a contactless IC card. This wireless communication enables the reader-writer and the RFID tag or the like to exchange data stored therein.
Further, as one of near-field wireless communication standards, there is a NFC (Near Field Communication) that uses a 13 MHz band frequency. It is hoped that NFC may be implemented in communication terminal apparatuses such as cellular phones and the like. For example, prevalence of NFC may allow a user to easily perform data transfer or data exchange only by moving his/her communication terminal apparatus close to a reader-writer provided at a shop to establish wireless communication between these two devices. Thus, NFC is now being studied to develop various applications such as contactless credit transactions and the like.
As a conventional example of devices that perform the foregoing wireless communication, there is a contactless tag described in Japanese Unexamined Patent Application Publication No. 2001-188890. This contactless tag is capable of recording received data and transmitting recorded data, and includes an antenna section for performing transmission and reception of data, an IC chip for processing data, and an impedance matching circuit for performing impedance matching between the antenna section and the IC chip.
Further, in some cases, a low pass filter (hereinafter, referred to as LPF) including an inductor element may be provided between the IC chip and the antenna section to suppress radiation of unwanted harmonics from the antenna section.
However, when an attempt is made to unify the antenna section and the inductor element of the LPF together and form a single module, there is a problem that magnetic coupling is formed depending on their spatial relationship and unwanted harmonics are radiated from the antenna section.